Which electrons are lost by an atom of iron when it forms the fe3+ ion?
a. one s orbital electron and two d orbital electrons
b. two s orbital electrons and one d orbital electron
c. three s orbital electrons
d. three d orbital electrons

How has the scientific community addressed the safety of chemicals? a. chemicals are repeatedly tested, even those that have existed for a long time. b. existing chemicals are tested if they have never been tested before. c. chemicals are tested if they are suspected to have caused a problem. d. only new chemicals are tested.

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

Calculate the frequency of a wave in a spring toy. the wave has a speed of 1.1 meters per second and a wavelength of 0.1 meters. *